81836379 has 16 divisors (see below), whose sum is σ = 121392000. Its totient is φ = 54488808.

The previous prime is 81836371. The next prime is 81836383. The reversal of 81836379 is 97363818.

It is a happy number.

81836379 is a `hidden beast` number, since 8 + 1 + 8 + 3 + 637 + 9 = 666.

It is not a de Polignac number, because 81836379 - 2³ = 81836371 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81836371) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28972 + ... + 31670.

It is an arithmetic number, because the mean of its divisors is an integer number (7587000).

Almost surely, 2^81836379 is an apocalyptic number.

81836379 is a deficient number, since it is larger than the sum of its proper divisors (39555621).

81836379 is a wasteful number, since it uses less digits than its factorization.

81836379 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3831 (or 3825 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The square root of 81836379 is about 9046.3461684815. The cubic root of 81836379 is about 434.1589934005.

It can be divided in two parts, 81836 and 379, that added together give a triangular number (82215 = T₄₀₅).

The spelling of 81836379 in words is "eighty-one million, eight hundred thirty-six thousand, three hundred seventy-nine".